P59 L31 Calibration Issues

[Fast355]

I have been running my 383 based on a L31 with a P59 using the 618 OS for a while now. I have run into two calibration problems that I would like to resolve.

#1) The AC will not work. I swapped to a GMT610 segment. The PCM reports the vehicle as AC equipped. The PCM sees the AC request. If the PCM has just been flashed it will enable the AC clutch for about 3 seconds. Then it will not re-enable the ac until a reflash. AC system works great with an 0411 in it and the system is wired correctly. I can enable the AC with Bi-Directional cpntrols. The PCM is not throwing a flag for the AC disabled due to WOT or Pressure.

#2)It will only use the Base Idle table and LTIT learned cells for Drive even if it is in Park/Neutral.

[Fast355]

After more research, I finally found a thread on LS1Tech that went over the P59 and A/C request settings. Halfway through the post there was a guy having the same issue I am having. The PCM sees the request, enables the compressor but shuts down the compressor within seconds. Turns out if you are converting from an application that had an actual pressure sensor to the basic 2 switch system, you have to disable P0530 by setting it to "NO ERROR REPORTED". The PCM interprets the missing pressure sensor signal as low refrigerant. Basically if you have the pressure sensor, P0530 needs to be set to "NO MIL" and if you have the High/Low pressure switches wired up you need P0530 set to "NO ERROR REPORTED". I have spent two afternoons messing with the thing. I have not tested it yet, however based off his results and post I believe that to be the A/C issue.

As for problem #2, I was looking for a P59 L31/Automatic file rather than a L31/Manual file, but it looks like GM possibly never offered the P59/L31 combination in anything but a Manual transmission truck. Something on the Engine side of the code is set to ignore anything to do with Park/Neutral air flow despite having copied values into every air flow and filter table I found associated and not populated using Universal Patcher. I have segment swapped the 4L80E transmission, transmission diagnostics, fuel system as well as System calibration from a 2005 GMT610 into the 2005 GMT800 5.7L L31 calibration. I had to re-enable the Low-Resolution crank sensor bit, disable the PRNDL so that the PCM would use the one in the valve body, and turn off the VATS. Runs and drives great, just want it to properly control the idle without dipping when I throw it into gear or jumping up when I throw it in park. I am assuming it is probably 1 calibration bit that is currently un-defined in the PCM coding.

[kur4o]

Did you look at this parameter,
Type_Of_Discrete_Gear_Select
It defines the prndl switch being used.

[Fast355]

Did you look at this parameter,
Type_Of_Discrete_Gear_Select
It defines the prndl switch being used.

I have. Set the same way as my 0411 was. No Switch. My van has never had the 4 wires to the PCM off the PRNDL. When the 4L60E and 4L80E are in use on an 0411 and No Switch is selected the 0411 uses the MPS mounted on the valve body to know what gear is selected. Just this evening, I found some transmission error codes that were not enabled the way GM had them enabled on the 2005 6.0L Van calibration I snagged the segments out of. I enabled those DTCs the same way. My L31/4L80E 0411 had the same DTCs enabled as well. Hopefully those missing or rather wrong DTC settings fix this issue as well.

The head scratching moment is the thing is using the MPS to run the transmission. I can manually select all gears and the transmission side of the code works perfectly with No Switch. It is just the engine side of the code that is currently confused. It cannot access the Park/Neutral idle air flow or idle spark tables. I had no issue getting it to do a Crank Relearn either.

I will reflash it with the new changes in the morning and post the results.

[kur4o]

This may also affect issue #2
Clutch_Switch_Type

What tables it needs to switch between, I may trace them in disassembly to see if there is any conditions that needs to be met.

[Fast355]

This may also affect issue #2
Clutch_Switch_Type

What tables it needs to switch between, I may trace them in disassembly to see if there is any conditions that needs to be met.

Needs to switch between the Base Running Airflow P/N and Drive as well as the Idle Spark Tables and adaptive learn for both. Double checked the clutch switch, same setting on the Mexican L31 is used in both the 0411 L31 file and the 2005 6.0L van. At the moment it is treating everything as being in Drive.

A/C is now working like it should. It also cycles as needed.